The invention relates to a process and apparatus for producing fibrous webs of at least two superposed web layers of equal or different structure by using at least two successively arranged cards. The fibrous web layers are discharged from the card or the like, and are supplied to a finishing or strengthening bonding unit, such as a calendar or the like.
It has been known, for doubling fibrous webs, to provide successively or side-by-side arranged cards for continuously supplying the fibrous webs to a common endless conveyor belt. The number of required cards is dictated by the required number of web layers. In the case of successively arranged cards, the machines are set up like a bridge above the conveyor belt. If the machines are arranged side-by-side, the fibrous web is deviated by about 90 degrees. There has been further known a card comprising a doffing point by which the fibrous web is subjected to multiple division, the divided web portions being discharged separately.
Devices for doubling and other devices for discharging fibrous webs side-by-said from one or more cards have in common that the order of superposed or side-by-side discharged fibrous webs remains unchanged in case of an existing machine assembly. It is possible to modify the fibrous web structure, if a plurality of machines or doffing points are available, in that the corresponding machine is exchanged against another. It is not possible, in one and the same assembly, to change the sequence of superposed or juxtaposed order of the fibrous webs without the need of completely converting the plant. In fact, concerning the layer position, a plant is conformed and adjusted to quite a specific product of multilayered fibrous webs. As a result thereof, the production of multilayered fibrous webs becomes rather inflexible.
It is the object of the invention to provide a process and apparatus in which it is posisble, with the use of one and the same machine assembly, to change the sequence or positioning of multiple fibrous webs.
Another object of the invention is to provide a process and apparatus for quickly and reliably producing, by simple means, fibrous webs having a completely different structural design with respect to the layers formed from the fibrous webs.